Wedge friction clutches including inner and outer races and a wedge plate disposed between the inner and outer races are known. It is known to engage and disengage such clutches according to relative rotation of the inner and outer races. However, such an arrangement limits controllability of the clutches. For instance, engaging and disengaging can only be accomplished for specific relative rotation combinations.
A wedge friction clutch with a resilient element to displace a wedge plate in a first circumferential direction for a locked mode (non-rotatably connecting inner and outer races) and with a circumferentially displaceable piston to displace the wedge plate in an opposite second circumferential direction for a free wheel mode (enabling relative rotation between the inner and outer races) is known. However, in the free wheel mode and for high relative acceleration between the inner race and the outer race, a high inertia load from the wedge ring and the outer race can push the piston back in the first circumferential direction, leading to an undesired transition from the free wheel mode to the locked mode, if the hydraulic system for the piston is not stiff enough or the hydraulic pressure on the piston is not high enough. Thus, either the available applications for the clutch are limited to low inertia operation or the energy budget for the clutch must be increased to provide the required hydraulic force to resist the inertial load.